Childhood major depressive disorder (MDD) may involve changes in limbic structures, since adult studies demonstrate functional and structural abnormalities and childhood MDD is clinically continuous with adult disorders. Magnetic resonance (MR) neuromorphometry of childhood MDD and controls is proposed to test this association. The aims are: 1) to determine whether frontal limbic circuit structural changes are present in childhood MDD, 2) measure the association between psychopathologic features and morphologic findings, and 3) estimate limbic structure developmental differences in MDD compared with control children. Prepubertal MDD children ages 8-12 will be matched by age, sex, handedness, IQ, and SES to normal controls. All subjects will be examined with 1) structured psychiatric interviews to determine DSM-IV diagnosis and 2) a tailored MRI protocol to acquire high resolution, three dimensional cerebral images. Subjects will be studied at baseline and an 18 month follow-up. MRI studies will be evaluated using stereologic sampling methods to determine regional volumes (temporal lobe, prefrontal cortex, parahippocampal gyrus, hippocampus, amygdala, caudate, lenticular and thalamic nuclei. This investigation will advance our understanding of frontal-limbic structural development in the presence of affective prepubertal psychopathology. This mentored research experience will combine Dr. Botteron's prior work with neuroimaging under a career development plan to provide in depth education including MR image processing, childhood MDD clinical investigations, and developmental neurobiology studies. Two preceptors will provide supervision and guidance: Dr. Michael Vannier in magnetic resonance neuroimaging, and Dr. Barbara Geller in childhood affective disorders. Structured coursework, seminars and consultation with experts in biostatistics, neuroradiology, neuroanatomy and neural circuitry are planned. The acquisition of these research skills and conceptual knowledge will facilitate Dr. Botteron's development as an independent psychiatric neuroimaging researcher and enable her to design and conduct longitudinal studies on child psychiatric disorders and brain development.